How can you keep horseflies away from a pool area?

So, I was swimming at my friends pool today, and 5 of us were bitten by horseflies multiple times. Is there any kind of natural repellent to keep horseflies away from their pool area? Also, they have a bunch of flowers around the pool, so if there is anyway to repel just the horseflies, and not the pollenating bees, that would be great.

They are not specific to just horses. They just like biting anything that has blood.

There are some fly traps with attractants that you could put outside your activity area. That might help eliminate some of the. There are sprays you can apply to keep the bugs off but getting in a pool washes most of them off and I don't like the feel of the sprays anyway.

You could try burning citronella candles or lamps. It fills the area with a citrus smell that either repels bugs or confuses them so that they have trouble finding you.